The invention relates to a volume control valve. Valves of this kind are well known, in which the external dimensions of such valves are chosen so that they can also be mounted in fittings which were originally designed for valve upper parts having an axially movable sealing cone. This results in extremely limited space for fitting the sealing disc and the seal between the fitting and the valve seat insert. In addition allowance has to be made for varying fitting depth tolerances of different fittings. Relatively complicated and expensive measures are therefore necessary in the case of the well known valves in order to achieve a sound seal of the valve insert with the supply inlet of the fitting.